Delivery Ticks (not blocked)

Registration date
Tuesday May 11, 2021
Last seen
May 11, 2021
Hi there, can someone please explain how messages can be sent on whats app, but they only show delivered when the recipient (me) opens whats app and reads them.

This has happened for the last three days, since i accepted their new terms.

A message was sent to me at midnight uk time, but it only showed delivered at the senders end when i looked at my phone at 6am, the phone was on all the time and the internet wasn't down.

It also happened to when i left my phone unattended deliberately for a few minutes, the same happened again. The phone is always on and always connected, and it not a block issue as the ticks do show eventually. This is causing stress and issues as the sender was worried something had happened to me, as their message wasn't delivered for several hours, yet my phone was on and had internet